I want to understand how focusing works in Manual mode in my D90. I switched off the autofocus buttons in the Kit lens and the camera body. I have changed to the manual mode. Now, when I try to focus on any specific object, I do not see any specific focus point being highlighted when I press the shutter button halfway. All the focus points on the view finders lights up in red and camera clicks immediately after pressing the shutter button fully.

I want to know why I am not able to focus on any specific object. For example, if I want to focus on the nearer object, so that the background is little blurred, then I dont seem to be able to do this. (I want to achive the 'Bokeh' effect)

I'm confused. In manual focus mode, you do the focusing. If you want to focus on a near object, turn the focus ring on a lens until it is in focus. What are you expecting to happen? (Is your question about how the focus indicator lights work while in manual focus mode?)
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mattdmJan 22 '12 at 12:58

For a question on how to achieve this effect in general, see this. But I think you're asking something different from that....
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mattdmJan 22 '12 at 15:35

2 Answers
2

If all the focus points are lighting up it's probably that all parts of the image are within the tolerance for the camera to consider them in focus. This is often the case with wide angle lenses and subjects of moderate distance from the camera. Essentially your depth of field is too large to be able to see clearly the difference between the in focus and out of focus parts of your image.

Achieving selective focus has been the subject of many questions here, but the short answer is to try:

focus on a really close subject

use the longest possible focal length (and shoot at the widest aperture)